add isanonymous, movetoname, decl[s], and nothing concept

1 files changed, 43 insertions, 5 deletions

diff --git a/starts/meaning-vm/level-1/sugar.cpp b/starts/meaning-vm/level-1/sugar.cpp
index eeb2eb0..24d59be 100644
--- a/starts/meaning-vm/level-1/sugar.cpp
+++ b/starts/meaning-vm/level-1/sugar.cpp
@@ -2,17 +2,14 @@
 
 #include "concepts.hpp"
 
+#include <stdexcept>
+
 using namespace intellect::level1;
 using namespace concepts;
 
 namespace intellect {
 namespace level1 {
 
-ref operator-(ref a, ref b)
-{
-	return ref(a.name() + "-" + b.name());
-}
-
 ref a(ref group)
 {
 	static unsigned long long gid = 0;
@@ -37,5 +34,46 @@ ref an(ref group, ref name)
 	return a(group, name);
 }
 
+bool isanonymous(ref topic)
+{
+	return topic.isa(concepts::anonymous);
+}
+
+ref movetoname(ref anonymous, ref name)
+{
+	if (!isanonymous(anonymous)) { throw std::invalid_argument("not anonymous"); }
+	if (isanonymous(name)) { throw std::invalid_argument("not named"); }
+	
+	// this only provides for writing to empty concepts, because merging concepts is
+	// best done with a knowledge of which links can be multiply attached, and that
+	// information is not available at this level.
+	bool nonempty = false;
+	for (auto & l : name.links()) {
+		if (l.first == concepts::name) { continue; }
+		nonempty = true;
+	}
+	if (nonempty) {
+		for (auto & link : anonymous.links()) {
+			if (link.first == concepts::is && link.second == concepts::anonymous) { continue; }
+			if (link.first == concepts::name) { continue; }
+			if (!name.linked(link.first, link.second)) {
+				throw std::logic_error(name.name() + " already defined otherwise from " + anonymous.get(concepts::is).name());
+			}
+		}
+	}
+	anonymous.unlink(concepts::is, concepts::anonymous);
+	auto nam = anonymous.get(concepts::name);
+	anonymous.unlink(concepts::name, nam);
+	if (!nonempty) {
+		for (auto & l : anonymous.links()) {
+			name.link(l.first, l.second);
+		}
+	}
+	anonymous.link(concepts::name, nam);
+	dealloc(anonymous);
+	dealloc(nam);
+	return name;
+}
+
 }
 }